What if you probed into the mind of a psychological conundrum and discovered nothing? This chilling idea is at the center of Molly Bell and Daya Curley's bright but rocky new musical, Becoming Britney.

The Britney in question is, of course, of the Spears variety, the prototypical current example of a celebrity living one long downward spiral. Once a darling of Star Search and The New Mickey Mouse Club, Spears didn't need much time in the spotlight's harshest glare for her natural talent to erode into institutional insanity. You know, the kind that leads to laughable virginity pledges, flings with Justin Timberlake and Kevin Federline, and shaving off her famous golden hair. Everyone was (and many probably still are) wondering how it could happen.

Lacking a complete set of answers, Bell and Curley have at least found an ideal location for fielding questions: a rehab center. Specifically, one called Promises, Promises, in which theatrical therapy is the order of the day. All Britney (Bell) must do to exorcise her own demons is to confront her own inner musical and guide the curtain down on her own terms - before it comes down on top of her. The resulting saga, which leads her from her mother (the fireplace-warm Riette Burdick) to Justin and K-Fed (a dynamic Keith Pinto) and then to children and emotional confusion, unfolds with jolting precision that highlights how rapidly an ordered life can devolve into chaos.

While Bell locates and contextualizes Spear's little-girl-lost temperament and self-destructive tendencies in her richly human portrayal, and the rest of the cast (which includes Carrie Madsen, Alison Ewing, and Sean Grady in a collage of colorful chorus roles) very nearly matches her, not everything comes easily. Bell and Curley (who also provides the spry direction) have particular trouble justifying their framing device, their shoehorning of musical theatre into the reluctant narrative more frequently amusing than successful. For example, Britney's singing her "I Want" song, "My I Want Song," about wanting an "I Want" song, is a brilliant dash of metatheatricality that doesn't expand our understanding of her plight; but her climactic "Here I'll Be" is a completely legitimate self-actualization showstopper.

Of special note are the opening and closing songs, which shed musical theatre in favor of Spears's preferred language: rock. She and her backup blast their vocals to a thumping soundtrack that further highlights Spears's defining disconnect between sentimentality and showmanship. And did I mention they're lip-synched? These numbers (and only these) are indeed pre-recorded, catching Spears's own tendency to sacrifice craft for performance, and forcing you to face how the famous rarely speak with their own voices. Becoming Britney is never better than when it's most directly asking whether Spears, after a life lived in the media, still has one at all.

Reminder to aspiring actors everywhere: If your dream role doesn't exist, you can indeed create it yourself. Randy Blair is living proof. He's far from conventional leading-man material, and with a piercing, trick-freak tenor placed somewhere between foghorn and coloratura, he seems ideal casting for Nicely-Nicely Johnson in Guys and Dolls... and not much else.

Yet as the title character in Perez Hilton Saves the Universe, the musical for which he wrote the lyrics and the book (the latter with Timothy Michael Drucker), he's a genuine star in the making. The infamous gossip blogger, best known for outing closeted public figures and doctoring their photos with carefully placed white pixels, becomes in his hands and voice a shimmering, sentimental symbol of all that's wrong - and all that's right - with the citizen-driven Web 2.0.

Strictly speaking, Blair is more dynamic as a performer than as a playwright. He plows his way through the show, never breaking a sweat in high-impact dance numbers, never losing his cool in micromanaged fight scenes, and never letting Perez become less than a lonely man who needs to be part of the culture he thrives on criticizing. Yet the specific story - a pair of Muslim terrorists plotting to nuke Los Angeles to end America's glittery grip on the world - feels like little more than a watery excuse for Blair and his crack cast mates to serve up some spicy impersonations.

These happen mostly on the periphery, but they're all dazzling (if sometimes borderline inauthentic): Andrew Keenan-Bolger is empty-headed perfection as Zac Efron and Tom Cruise; Ana Nogueira is a kick as the barely there Paris Hilton; Lindsay Nicole Chambers is an upper as the coked-up Amy Winehouse; and Jason Veasey finds bizarre breadth in both R. Kelly and Jaleel White (yes, Steve Urkel). Laura Jordan elevates Kathy Griffin - a major character with even more major complexes - to such extravagant heights of absurdity, she at times threatens to eclipse the real comedienne's vivid personality.

The music (by Zach Redler) is mostly functional, anxious pop that pops but rarely lingers in your ear. And director-choreographer Connor Gallagher could smooth out some of the seismic differences in tone that prevent Perez Hilton Saves the Universe from feeling like a fully integrated (or finished) evening. Blair, however, never gives you cause or time to worry about where you're going; he's too busy making sure your ride is a wild one. On that score, he never lets you down and, like the real Hilton, he always leaves you buzzing about what's coming up next.